SLIDE 1
Kevin W. McElhaney, Gautam Biswas, Jennifer L. Chiu STEM+C PI Summit Challenges Showcase September 19, 2019
Mathematical Complexity of Computational Modeling Experiences for Elementary Students
SLIDE 2 Curricular context: Modeling urban water runoff
- Multi-week, 5th grade curriculum unit integrating
earth science, engineering, and computational thinking (NGSS PEs 5-ESS3-1, 3-5ETS1-3)
- Students develop a computational model of water
runoff and use it to test and refine engineering solutions
SLIDE 3
Designing the runoff model
Runoff model
Science DCIs (Human impacts/ Runoff) SEPs (e.g., modeling, information, investigation) CCCs (e.g., Systems and system models, matter) Engineering DCIs (e.g., develop, test, refine solutions) CT concepts & practices (e.g., creating and testing computational artifacts, loops, variables…)
SLIDE 4
Basic runoff system model
s u r f a c e rainfall absorption (material dependent) runoff (rainfall – absorption)
SLIDE 5
Runoff algorithm (time dependent)
set StormDuration to... set ElapsedTime to 0 set HourlyRainfall to... set TotalAbsorption to 0 set TotalRunoff to 0 set TotalRainfall to 0 set AbsorptionCoeff to... Repeat until (ElapsedTime is equal to StormDuration) change ElapsedTime by 1 change TotalRainfall by HourlyRainfall change TotalAbsorption by ... set TotalRunoff to TotalRainfall – TotalAbsorption
variable initialization simulation with stopping condition
SLIDE 6
Runoff algorithm (time dependent)
set StormDuration to... set ElapsedTime to 0 set HourlyRainfall to... set TotalAbsorption to 0 set TotalRunoff to 0 set TotalRainfall to 0 set AbsorptionCoeff to... Repeat until (ElapsedTime is equal to StormDuration) change ElapsedTime by 1 change TotalRainfall by HourlyRainfall change TotalAbsorption by ... set TotalRunoff to TotalRainfall – TotalAbsorption
Temporal variables require reasoning about rates and durations
SLIDE 7
Runoff algorithm (time dependent)
set StormDuration to... set ElapsedTime to 0 set HourlyRainfall to... set TotalAbsorption to 0 set TotalRunoff to 0 set TotalRainfall to 0 set AbsorptionCoeff to... Repeat until (ElapsedTime is equal to StormDuration) change ElapsedTime by 1 change TotalRainfall by HourlyRainfall change TotalAbsorption by ... set TotalRunoff to TotalRainfall – TotalAbsorption
Hourly vs. total variables
SLIDE 8
Runoff algorithm (time dependent)
set StormDuration to... set ElapsedTime to 0 set HourlyRainfall to... set TotalAbsorption to 0 set TotalRunoff to 0 set TotalRainfall to 0 set AbsorptionCoeff to... Repeat until (ElapsedTime is equal to StormDuration) change ElapsedTime by 1 change TotalRainfall by HourlyRainfall change TotalAbsorption by ... set TotalRunoff to TotalRainfall – TotalAbsorption
“set” vs. “change”
SLIDE 9
Runoff algorithm (time dependent)
set StormDuration to... set ElapsedTime to 0 set HourlyRainfall to... set TotalAbsorption to 0 set TotalRunoff to 0 set TotalRainfall to 0 set AbsorptionCoeff to... Repeat until (ElapsedTime is equal to StormDuration) change ElapsedTime by 1 change TotalRainfall by HourlyRainfall change TotalAbsorption by ... set TotalRunoff to TotalRainfall – TotalAbsorption
Repeat until (stopping condition) is challenging
SLIDE 10
Runoff algorithm (not time dependent)
SLIDE 11
Runoff algorithm (not time dependent)
set TotalRainfall to... set AbsorptionLimit to... if (TotalRainfall is equal to AbsorptionLimit) set TotalAbsorption to TotalRainfall set TotalRunoff to 0 if (TotalRainfall is less than AbsorptionLimit) set TotalAbsorption to TotalRainfall set TotalRunoff to 0 if (TotalRainfall is greater than AbsorptionLimit) set TotalAbsorption to AbsorptionLimit set TotalRunoff to TotalRainfall – TotalAbsorption
SLIDE 12
Runoff algorithm (not time dependent)
set TotalRainfall to... set AbsorptionLimit to... if (TotalRainfall is equal to AbsorptionLimit) set TotalAbsorption to TotalRainfall set TotalRunoff to 0 if (TotalRainfall is less than AbsorptionLimit) set TotalAbsorption to TotalRainfall set TotalRunoff to 0 if (TotalRainfall is greater than AbsorptionLimit) set TotalAbsorption to AbsorptionLimit set TotalRunoff to TotalRainfall – TotalAbsorption
No rate-based or temporal variables
SLIDE 13
Runoff algorithm (not time dependent)
set TotalRainfall to... set AbsorptionLimit to... if (TotalRainfall is equal to AbsorptionLimit) set TotalAbsorption to TotalRainfall set TotalRunoff to 0 if (TotalRainfall is less than AbsorptionLimit) set TotalAbsorption to TotalRainfall set TotalRunoff to 0 if (TotalRainfall is greater than AbsorptionLimit) set TotalAbsorption to AbsorptionLimit set TotalRunoff to TotalRainfall – TotalAbsorption
No “change”
SLIDE 14
Runoff algorithm (not time dependent)
set TotalRainfall to... set AbsorptionLimit to... if (TotalRainfall is equal to AbsorptionLimit) set TotalAbsorption to TotalRainfall set TotalRunoff to 0 if (TotalRainfall is less than AbsorptionLimit) set TotalAbsorption to TotalRainfall set TotalRunoff to 0 if (TotalRainfall is greater than AbsorptionLimit) set TotalAbsorption to AbsorptionLimit set TotalRunoff to TotalRainfall – TotalAbsorption
Simpler conditions; no nesting
SLIDE 15
Designing the runoff model
Runoff model Science DCIs (Human impacts/ Runoff) SEPs (e.g., modeling, information, investigation) CCCs (e.g., Systems and system models, matter) Engineering DCIs (e.g., develop, test, refine solutions) CT concepts & practices (e.g., programming, algorithms, variables…)
SLIDE 16
Designing the runoff model
Runoff model Science DCIs (Human impacts/ Runoff) SEPs (e.g., modeling, information, investigation) CCCs (e.g., Systems and system models, matter) Engineering DCIs (e.g., develop, test, refine solutions) CT concepts & practices (e.g., programming, algorithms, variables…)
Grade-appropriate mathematics concepts
SLIDE 17 Summary
- Computational modeling experiences are
constrained by grade-appropriate mathematics concepts, especially in elementary
- Designers may be challenged to align multiple
educational frameworks (NGSS, CS Framework, CCSSM) at specific grade levels
- Argues for a broad definition of “computational
model” for STEM+C education
- model that leverages computational affordances (e.g.,
facilitates rapid testing and iterative refinement)
SLIDE 18 Project team
SR SRI
- Nonye Alozie
- Satabdi Basu
- Ron Fried
- Reina Fujii
- HeeJoon Kim
- Jennifer Knudsen
- Beth McBride
UV UVA
- Chris Dittrick
- Sarah Fick
- James Hong
- Sarah Lilly
- Anne McAlister
Vanderbilt ilt
Acknowledgements: This material is based upon work supported by the National Science Foundation under Grant No. DRL-
- 1742195. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and
do not necessarily reflect the views of the National Science Foundation.